Navigation menu not visible (contrast issue) on home page

If you inspect the element, you’ll see that header has a different background color than other pages which is transparent. Your nav elements color is also white and that is why you can’t see the menus on home page but actually the menu is there. Just change the header background color to #000 as you used for other page header. So you can add following css to your style:

#masthead .site-header{
    background-color: #000;
}